Steps to Reproduce:

• Create a test project (I'm creating a project with name JQL).
• Create a "Text Field (< 255 characters)/Single/Multi" custom field called "Text Single" -> Any name
• Assign it to the test project fields configuration context. (or in Global Context)
• Add "Text Search" to projects screens
• Create an issue with "Text Single" = A and Summary = A in the test project.
• Execute JQL - Search:

  project=JQL and "Text Single" ~ A
  
  project=JQL and summary ~ A
  

  

• => no issue is found (expected to find the previously created issue)
• Create an issue with "Text Single" = B and search with

  project=JQL and "Text Single" ~ B
  

  

• => created issue is found
• Create an issue with "Text Single" = AA and search with

  project=JQL and "Text Single" ~ AA
  

  

• => created issue is found!

Expected Results:
All the query will listed the issue in the issue navigator.

Actual Results:
The issue is not listed only for issue with value of A.

Notes:
Summary field also give the same result.